Ground screw adaptor for solar panel support structure

ABSTRACT

An adaptor for connecting a ground screw to an upright beam of a solar panel support assembly includes (a) a cylindrical connector having an open ground-screw receiving bottom end and a top end, the cylindrical connector having an inner circumferential surface with a diameter slightly larger than that of the ground screw and at least two sets of bolt holes, each set of bolt holes including at least three bolt holes uniformly distributed circumferentially about the cylindrical connector at an axial level, and the at least two sets of bolt holes being axially distanced from one another; (b) an intermediate plate having a top surface and a bottom surface fixed to the top end of the cylindrical connector; and (c) an upright beam connector fixed to the top surface of the intermediate plate and extending upward from the intermediate plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional application of U.S. patent applicationSer. No. 17/218,899 filed Mar. 31, 2021, the entire disclosure of whichis incorporated herein by reference.

BACKGROUND

Modern solar panel systems provide photovoltaic or other sunlightreceiving panels (such as mirrors for solar-thermal systems) supportedon assemblies to receive and convert solar energy. The solar panels aretypically large, relatively heavy, rectangular and planar panels. Mostsolar panel systems support multiple solar panels with solar panelsupport assemblies.

Fixed tilt system support assemblies support the solar panels at a fixedangle selected to have an optimum exposure to sunlight.

Solar tracking system support assemblies rotate solar panels to trackthe motion of the sun over the course of the day. Horizontal,single-axis solar trackers are often the most cost effective, as suchtrackers can simply rotate solar panels to face from east to west, totrack the sun over the course of the day. Then at night, they can returnto the stow position to repeat this standard cycle starting thefollowing day.

Dual-axis trackers are also used to provide the tracking function forphotovoltaic panels. The dual-axis trackers share the basic trackingfunction for east-west with the single-axis trackers. In addition to theeast-west tracking function, a dual-axis tracker can also add someadjustment in the north-south direction. This allows the dual-axistracker to more closely follow the position of the sun throughout theyear and better adjust for Latitude and season. The single-axis trackermay be considered as a subset of the dual-axis tracker function andconfiguration. The dual-axis tracker includes the function of thesingle-axis tracker plus it has another degree of freedom to adjust thenorth-south angle and more closely track the sun for greater energycapture.

Such solar panel support assemblies experience significant mechanicalstress due to weight, terrain, wind-loading, thermal expansion and otherweather- or terrain-related events.

Many solar panel support assemblies are built on piers that are anchoredto the ground or to some other surface. For those piers that areanchored to the ground, ground screws may be used as the anchor.

SUMMARY

Embodiments of the current disclosure provide novel ground screwadaptors for connecting upright beams of a solar panel support structure(or a similar framework) to anchored ground screws (or to some otheranchor), and associated method for use/installation.

An aspect of the current disclosure provides an adaptor for connecting aground screw to an upright beam of a solar panel support assembly. Suchadaptor includes (a) a cylindrical connector having an open ground-screwreceiving bottom end and a top end, the cylindrical connector having aninner circumferential surface with a diameter slightly larger than thatof the ground screw and at least two sets of bolt holes, each set ofbolt holes including at least three bolt holes uniformly distributedcircumferentially about the cylindrical connector at an axial level, andthe at least two sets of bolt holes being axially distanced from oneanother; (b) an intermediate plate having a top surface and a bottomsurface fixed to the top end of the cylindrical connector; and (c) anupright beam connector fixed to the top surface of the intermediateplate and extending upward from the intermediate plate. In a moredetailed embodiment, each set of bolt holes includes three bolt holesdistributed 120° apart about the circumference of the cylindricalconnector. In a further detailed embodiment, the adaptor includes twosets of the bolt holes axially separated at least about 2 or 3 inchesapart, and in a specific embodiment are separated about 5 inches apart.

Alternatively, or in addition, the cylindrical connector, theintermediate plate and upright beam connector are welded together.Alternatively, or in addition, the upright beam connector includes abox-channel bracket extending from the intermediate plate and includinga plurality of bolt holes.

In another aspect, an adaptor for connecting an anchor to an uprightbeam of a racking assembly subject to upward forces, downward forces andmoment forces, includes: (a) a hollow connector having an open anchorreceiving bottom end and a top end, the hollow connector having an innersurface that is shaped complementary to an outer surface of the anchorwith dimensions slightly larger than that of anchor so that the anchormay be received in the bottom end of the hollow connector in atelescoping fashion, and at least two sets of bolt holes, each set ofbolt holes including at least three bolt holes uniformly distributedabout a perimeter of the hollow connector at an axial level, and the atleast two sets of bolt holes being axially distanced from one another;(b) an intermediate plate having a top surface and a bottom surfacefixed to the top end of the hollow connector; and (c) an upright beamconnector fixed to the top surface of the intermediate plate andextending upward from the intermediate plate. In a more detailedembodiment, each set of bolt holes includes three bolt holes distributed120° apart about the perimeter of the hollow connector. In a furtherdetailed embodiment, the adaptor includes two sets of the bolt holesaxially separated at least about 2 or 3 inches apart, and in a specificembodiment are separated about 5 inches apart.

In another aspect, a method for mounting an upright beam of a of a solarpanel support assembly to an anchored ground screw is provided thatincludes steps of (in no specific order unless otherwise required): (1)providing an adaptor including (a) a hollow connector having an openanchor receiving bottom end and a top end, the hollow connector havingan inner surface that is shaped complementary to an outer surface of theanchor with dimensions slightly larger than that of anchor so that theanchor may be received in the bottom end of the hollow connector in atelescoping fashion, and at least two sets of bolt holes, each set ofbolt holes including at least three bolt holes uniformly distributedabout a perimeter the hollow connector at an axial level, and the atleast two sets of bolt holes being axially distanced from one another,(b) an intermediate plate having a top surface and a bottom surfacefixed to the top end of the hollow connector, and (c) an upright beamconnector fixed to the top surface of the intermediate plate andextending upward from the intermediate plate; (2) telescoping the hollowconnector over the anchor such that the intermediate plate rests on atop surface of the anchor; (3) tightening set screws in the two sets ofbolt holes such that the set screws provide frictional force against theouter surface of the anchor; and (4) coupling an upright beam of thesolar panel support assembly to the upright beam connector. In adetailed embodiment the method further includes a step of (4) assemblingthe solar panel support assembly to the coupled upright beam; andfollowing the assembling step, (5) torqueing at least some of the setscrews further against the outer surface of the anchor. In a furtherdetailed embodiment, the torqueing step (5) causes mechanicaldeformation of the outer surface of the anchor.

Alternatively, or in addition, each set of bolt holes includes threebolt holes distributed 120° apart about the circumference of the hollowconnector. Alternatively, or in addition, the adaptor includes two setsof the bolt holes axially separated at least about 2 or 3 inches apart,and in a specific embodiment are separated about 5 inches apart.Alternatively, or in addition, the hollow connector, the intermediateplate and upright beam connector are welded together. Alternatively, orin addition, the upright beam connector includes a box-channel bracketextending from the intermediate plate and including a plurality of boltholes; and the step (4) of coupling an upright beam of the solar panelsupport assembly to the upright beam connector includes a step of (4a)telescoping a box-channel upright beam with respect to the box-channelbracket and coupling the box-channel upright beam to the upright beamconnector with multiple bolts and nuts. In a more detailed embodiment,the step (4a) of telescoping the hollow connector over the anchor suchthat the intermediate plate rests on a top surface of the anchorincludes a step of (4b) orienting the box-channel bracket such that amiddle plate of the box-channel bracket is substantially parallel to anorth-south direction. Alternatively, or in addition, the inner surfaceof the hollow connector is dimensioned at least about ¼ inches largerthan that of anchor and the method includes a step of gimballing hollowconnector with respect to the anchor using spacing provided by thedifferent dimensions. In a more detailed embodiment, the anchor andhollow connector are cylindrical and the inner surface of the hollowconnector has a diameter that is at least about ¼ inches larger than thediameter of the anchor and the method includes a step of gimballinghollow connector with respect to the anchor using spacing provided bythe different diameters.

These and other aspects and objects of the current disclosure will beapparent from the following description, the appended claims and theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a perspective view of an exemplary solar panel supportstructure;

FIG. 2 provides a close-up view of the exemplary support structure ofFIG. 1 , including exemplary ground screw adaptors connecting thesupport structure to ground screws;

FIG. 3 perspective, exploded view of an exemplary ground screw adaptorfor connecting a vertical support of a solar panel support structure toa ground screw; and

FIG. 4 is an assembled view of FIG. 3 shown from an oppositeperspective.

DETAILED DESCRIPTION

FIG. 1 provides a perspective view of a fixed tilt system supportassembly 10 for supporting solar panels at a fixed angle selected tohave an optimum exposure to sunlight. Typically, this fixed angle wouldbe directed towards the equator (so that the solar panels have optimumexposure to sunlight). The fixed tilt solar panel support assembly 10includes a plurality of vertical piers or posts 12 which support aracking framework 14 onto which solar panels (not shown) are mounted.While the exemplary embodiments discussed herein pertain to a fixed tiltsystem, it will be apparent to those of ordinary skill that thedisclosure is also relevant to solar tracking systems, other solar panelsupport framework assemblies, as well as other large frameworkassemblies subject to the same sorts of mechanical stresses (upliftforces, downward forces and moment transfer) discussed herein.

FIG. 2 is a perspective, close-up view of a pair of the vertical supportposts/piers 12 supporting and being coupled to a tilted beam 16 of thetilt system solar panel support assembly framework 14. Each of thevertical support posts/piers 12 include a ground screw 18 anchored intothe ground (screwed, or otherwise embedded into the ground) and adapterassembly 20 mounted on a top end of the ground screw 18 and a boxchannel upright beam 22 mounted to the top end of the adapter assembly20. The tilted beam 16 is in turn mounted to the top end of the boxchannel upright beams 22 as shown in FIG. 2 .

FIGS. 3 and 4 provide details of the adapter assembly 20 and how theadapter assembly 20 mounts the upright beams 22 over the ground screws18. FIG. 3 is an exploded view illustrating this coupling while FIG. 4is a close-up perspective view of the coupling provided by the adapter20. The adapter 20 for connecting the ground screw 18 to a verticalupright beam 22 of the solar panel support assembly includes acylindrical connector 24, an intermediate plate 26 and an elongatedupright beam connector 28. The hollow cylindrical connector 24 has anopen ground screw receiving bottom end 30 and a top end 32. Thecylindrical connector 24 has an inner circumferential surface (notshown) with a diameter that is larger than that of the ground screw 18so that the cylindrical connector 24 can be received over the top end ofthe ground screw 18 in a telescoping fashion. The cylindrical connector24 includes at least two sets 34, 36 of bolt holes 38 where each set 34,36 of bolt holes 38 include at least three of such bolt holes 38uniformly distributed circumferentially about the cylindrical connector24 at a given axial level such that the lower set 34 of bolt holes 38 isaxially distanced from the upper set 36 of bolt holes 38. In anexemplary embodiment, each set 34, 36 of bolt holes 38 includes three ofsuch bolt holes 38 distributed 120° apart about the circumference of thecylindrical connector. In an embodiment, these two sets 34, 36 of boltholes 38 are axially separated from each other by at least two or threeinches and are separated by about 5 inches in the specific embodimentillustrated. In other embodiments, the axial separation of the two sets34, 36 of bolt holes 38 may be 6 inches, 8 inches or even more. As willbe appreciated, the greater the axial separation, the greater theassembly will be able to withstand uplift and moment forces on thestructure.

In a specific embodiment, the cylindrical connector 24 has an innercircumferential surface (not shown) that is about 3.5 inches, whileouter diameter of the ground screw 18 at its top end (the portion thatmates in a telescoping fashion with the cylindrical connector 24) has anouter diameter of about 3 inches. This difference in diameters leavesabout ¼ inch radial separation between the cylindrical connector 24 andthe cylindrical top end of the ground screw 18 when the cylindricalconnector 24 and the ground screw are coaxial. This diametrical/radialseparation permits gimballing or rotational capacity for making theuprights plumb as will be described further below.

The intermediate plate 26 may be welded onto the top end 32 of thecylindrical connector 24. The intermediate plate 26 has a top surface 40and a corresponding bottom surface 42 where the bottom surface may bewelded to the top of the cylindrical connector 24 and the top surface 40may be welded to the upright beam connector 28. While the intermediateplate 26 is welded to the cylindrical connector 24 and upright beamconnector 28 in an exemplary embodiment, it will be apparent to those ofordinary skill that the intermediate plate 26 may be integrallyconnected, fixed or securely coupled to either or both of thecylindrical connector 24 and upright beam connector 28 in otherembodiments.

The upright beam connector 28 welded to the top surface 40 of theintermediate plate 26 extends upward from the intermediate plate 26. Inan exemplary embodiment, the upright beam connector 28 is in the form ofa Box-channel configured to engage with a corresponding Box-channelstructure of the upright beam 22. In the exemplary embodiment, theupright beam connector 28 includes a plurality of bolt holes 44positioned to be aligned with a selected plurality of bolt holes 46 inthe Box-channel upright 22. The upright beam connector 28 and theupright 22 may be coupled to each other with corresponding bolts 52 andnuts 54, where the bolts 52 extend through aligned bolt holes 44, 46.

It will be apparent to those of ordinary skill that the upright beamconnector 28 connector may be designed in other embodiments to mate withand couple to different designs of upright beams as known in the art (oras become available in the art). Similarly, it will be apparent to thoseof ordinary skill that the cylindrical connector 24 may be a hollowconnector (with an open bottom) having a different internal shape tomatch and telescope of a complementary shaped ground screw top end (forexample, and without limitation, octagonal shapes, rectangular/squareshapes, oval shapes, star shapes and the like). Similarly, it is withinthe scope of the current disclosure that the telescoping engagementbetween the cylindrical connector 24 and the top end of the ground screw18 be swapped, while still maintaining many of the advantages of theillustrated embodiment. For example, it will be appreciated that thecylindrical connector 24 may be a cylinder (or alternate shape) thattelescopes within a cylindrical (or alternate shaped) hollow top end ofthe ground screw 18, where the ground screw contains the two sets 34, 36of bolt holes rather than the cylindrical connector.

An example process for installing the vertical uprights 22 to the groundscrew 18 that has been securely anchored into a ground surface is asfollows: First, place the ground screw adapter 20 over the cylindricaltop end of the installed ground screw 18 in a telescoping fashion suchthat the intermediate plate 26 of the adapter 20 is resting on the topsurface 48 of the ground screw 18 and that the box-channel middle plate56 of the upright beam connector 28 is oriented parallel to thenorth/south direction. Next, set bolts 50 are placed through the boltholes 38 of the cylindrical connector 24 such that all six set bolts 50are in firm contact with the outer cylindrical surface of the groundscrew 18 and that the adapter 20 is plumb in all directions. Plumbingthe adapter 20 can be achieved by adjusting the set bolts 50 to varyingdepths to account for gimballing the adaptors 24 with respect to groundscrew installations that may be out-of-plumb. The set bolts 50 need onlybe finger-tight at this time. With the adapters 20 in place,installation of the upright beams 22 occurs next. The upright beams 22are installed by sliding/telescoping the Box-channel of the upright beam22 over top of the Box-channel portion of the upright beam connector 28.The uprights 22 are thereafter adjusted vertically as needed to permitalignment of the upper racking structure 14 and then bolts/nuts 52, 54are installed fastening the upright 22 to the upright beam connector 28.Next, racking 14 construction occurs after the racking structure 14 iserected and aligned, the set bolts 50 are torqued such that they may besufficiently friction fit and/or embedded into the cylindrical surfaceof the ground screw 18 (in an embodiment, the bolts 50 are torquedsufficiently so that they begin to mechanically deform outercircumferential surface of the ground screw).

Some features and benefits of the exemplary adapter assembly 20 include,for example, simple installation. Racking can be constructed beforefinal plumbing and tightening of the adapters. Further, no specialfabrication is needed on the ground screw. In an embodiment, the uprightbeam connector 28 eliminate the need for East/West and North/Southbracing (up to approximately 90 psf snow, 130 mph wind in an embodimentdepending upon tilt angle and panel size). The exemplary embodimentallows for ⁺/⁻3.5% out-of-plumb tolerance for ground screw installation.The exemplary embodiment allows for unlimited rotational tolerance forscrew installation. The exemplary embodiment allows for several inchesof vertical adjustment permitted at the connector 28 to upright 22connection. The six-bolt set screw type connection used by the exemplaryadapter provides secure connection from adapter 20 to ground screw 18.The bolts 50 may be provided pre-installed in the adapter 20 in tappedholes 38. The set bolts 50 may be standard hardware and require nospecial tools. Further, the intermediate plate 26 of the adapter 20rests atop the ground screw top surface 48 providing no concern forslipping over time.

The intermediate plate 26 allows for transition from ground screw to boxchannel upright as discussed above. This also eliminates risk of slip byproviding a hard stop over the ground screw 18. The cylindricalconnector 24 envelopes the top of the ground screw 18 and is securedwith six set bolts 50. In the exemplary embodiment, this permits 3.5° ofrotation with respect to plumb and unlimited twist adjustment about theground screw 18.

The telescoping upright beam connector 28 allows several inches of totalvertical adjustment of about +/−2.5 inches in the illustratedembodiment; but it will be appreciated that different (unlimited)vertical adjustment capabilities of the upright beam connector 28 willdepend upon the type, shape and design of the vertical upright 22 towhich the upright beam connector 28 is adapted to be connected.

The box channel uprights used for the vertical uprights 22 may be madefrom pre-galvanized material and potentially roll-formed for high volumeproduction.

The adapter assembly 20, according to the exemplary embodiments, isbeneficial to allow the racking construction 14 to withstand multipletypes of forces. Uplift forces (caused by wind, for example) areresisted between the ground screw 18 and the adaptor 20 due to thetelescoping connection between the ground screw 18 and the adaptorsecured by two vertically separated sets 34, 36 of three set bolts 50spaced 120° about the circumference of the ground screw. When upliftforces in the installed vertical upright 22 pull on the adaptorvertically, the set bolts 50 resist the uplift forces through friction.If loaded heavily enough, the set bolts 50 will begin to plow the groundscrew material. Downward forces are resisted by way of the intermediateplate 26 of the adaptor 20 resting on the top surface 48 of the groundscrew. In this case, there is no reliance on the set bolts 50 to resistforces acting in a downward direction on the connection. Moment transferforces are resisted between the ground screw 18 and the adaptor 20 dueto the telescoping connection between the ground screw 18 and theadaptor secured by two vertically separated sets 34, 36 of three setbolts 50 spaced 120° about the circumference of the ground screw. Priorart ground screw-to-post connection rely on just three set bolts (onevertical level), which permits the telescoping round post to pivotwithin the ground screw because the connection has a near-zero“development length.” Because the exemplary adaptor 20 has twovertically separated sets 34, 36 of set bolts 50 spaced sufficiently farapart, the connection has greater development length, which enables theconnection to adequately transfer bending moments from the verticaluprights 22 to the ground screw foundation.

Having described the embodiments of the current disclosure withreference to the above specification and the attached drawings, it willbe apparent to those of ordinary skill that modifications may be madewithout departing from the scope of the disclosed inventions as definedby the following claims. Further it is not intended that any details ofthe above disclosure be incorporated into the meaning of the claimsunless specifically set forth in the language of the claims.

What is claimed is:
 1. A method for mounting an upright beam of a of asolar panel support assembly to an anchored ground screw, comprisingsteps of: providing an adaptor including (a) a hollow connector havingan open anchor receiving bottom end and a top end, the hollow connectorhaving an inner surface that is shaped complementary to an outer surfaceof the anchor with dimensions slightly larger than that of anchor sothat the anchor may be received in the bottom end of the hollowconnector in a telescoping fashion, and at least two sets of bolt holes,each set of bolt holes including at least three bolt holes uniformlydistributed about a perimeter of the hollow connector at an axial level,and the at least two sets of bolt holes being axially distanced from oneanother, (b) an intermediate plate having a top surface and a bottomsurface fixed to the top end of the hollow connector, and (c) an uprightbeam connector fixed to the top surface of the intermediate plate andextending upward from the intermediate plate; telescoping the hollowconnector over the anchor such that the intermediate plate rests on atop surface of the anchor; tightening set screws in the two sets of boltholes such that the set screws provide frictional force against theouter surface of the anchor; and coupling an upright beam of the solarpanel support assembly to the upright beam connector.
 2. The method ofclaim 1, further comprising steps of: assembling the solar panel supportassembly to the coupled upright beam; and following the assembling step,torqueing at least some of the set screws further against the outersurface of the anchor.
 3. The method of claim 2, wherein the torqueingstep causes mechanical deformation of the outer surface of the anchor.4. The method of claim 1, wherein each set of bolt holes includes threebolt holes distributed 120° apart about the perimeter of the hollowconnector.
 5. The method of claim 1, comprising two sets of the boltholes axially separated at least about 3 inches apart.
 6. The method ofclaim 5, wherein the two sets of the bolt holes are axially separated atleast about 5 inches apart.
 7. The method of claim 1, wherein the hollowconnector, the intermediate plate and upright beam connector are weldedtogether.
 8. The method of claim 1, wherein: the upright beam connectorincludes a box-channel bracket extending from the intermediate plate andincluding a plurality of bolt holes; and the step of coupling an uprightbeam of the solar panel support assembly to the upright beam connectorincludes a step of telescoping a box-channel upright beam with respectto the box-channel bracket and coupling the box-channel upright beam tothe upright beam connector with multiple bolts and nuts.
 9. The methodof claim 8, wherein the telescoping the hollow connector over the anchorsuch that the intermediate plate rests on a top surface of the anchorincludes a step of orienting the box-channel bracket such that a middleplate of the box-channel bracket is substantially parallel to anorth-south direction.
 10. The method of claim 1, wherein inner surfaceof the hollow connector is dimensioned at least about ¼ inches largerthan that of anchor and the method includes a step of gimballing hollowconnector with respect to the anchor using spacing provided by thedifferent dimensions.
 11. The method of claim 10, wherein the anchor andhollow connector are cylindrical and the inner surface of the hollowconnector has a diameter that is at least about ¼ inches larger than thediameter of the anchor and the method includes a step of gimballinghollow connector with respect to the anchor using spacing provided bythe different diameters.